Pour the bag of baby spinach into a large salad bowl and fluff the leaves gently with your hands.
Cut the chicken breast into small bite‑size pieces, then season with Herbes de Provence, salt, and black pepper. Cook the chicken in a dry nonstick skillet (or lightly greased) over medium heat for about 8–10 minutes, stirring occasionally, until golden and cooked through.
Carefully peel the pomegranate and remove the arils, collecting them in a separate bowl and discarding the white membrane.
Let the cooked chicken cool slightly, then add it to the bowl with spinach. In a small bowl, whisk together olive oil, fresh lemon juice, salt, and pepper to make a simple dressing.
Drizzle the dressing over the salad and toss gently to combine, making sure every leaf is lightly coated, then sprinkle the pomegranate seeds generously over the top before serving.